This study was performed to investigate the effectiveness of garlic and onion compared to butylated hydroxy toluene (BHT) on retarding oxidation of cold infused sunflower oil stored for 6 months. Garlic and onion powders or their essential oils were added to sunflower oil in a wide range of concentrations. Sensory evaluation of the flavored oil samples was carried out. Panelists preferred significantly the sunflower oil flavored by cold infusion with garlic and onion powders at 5% and 10 % levels or their essential oils at 0.01% and 0.02% levels. The progress of oxidation was assessed in terms of acid value, peroxide value, and oxidative stability determined by Rancimat. The yield and Gas Chromatography-Mass Spectrometry analysis of the garlic and onion essential oils were determined. These results suggested that garlic or onion could be used as a natural flavoring material for improving oxidative stability of sunflower oil.